Scandium oxide

Scandium(III) oxide
Other names Scandia, scandium sesquioxide
Identifiers
CAS number	12060-08-1 Y
PubChem	4583683
Properties
Molecular formula	Sc2O3
Molar mass	137.91 g/mol
Density	3.86 g/cm3
Melting point	2485 °C
Solubility in other solvents	Insoluble
Hazards
NFPA 704	0 1 0
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Scandium(III) oxide, Sc₂O₃, scandia is a high melting white solid used in high-temperature systems (for its resistance to heat and thermal shock), electronic ceramics, and glass composition (as a helper material).

Physical and chemical properties

Scandium(III) oxide has the C-M₂O₃ structure like the α-Mn₂O₃ which contains 6- coordinate metal centers.^[1] Scandium(III) oxide can be prepared by igniting the metal.^[2]

Sc₂O₃ is amphoteric, dissolving in acids and alkalis.^[2]

It is converted into scandium(III) chloride by reaction with excess aqueous HCl or aqueous HCl/NH₄Cl mixtures.^{[citation needed]}

Sc₂O₃ + 6 HCl → 2 ScCl₃ + 3 H₂O

With alkalis it forms scandate salts, unlike its higher homologues yttrium oxide and lanthanum oxide, for example forming K₃Sc(OH)₆ with KOH. In this, scandium shows more similarity with aluminium oxide.^[2]

It is converted into the Lewis acid scandium(III) triflate by reaction with triflic acid.^[3]

References

1. ^ Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
2. ^ ^{a b c} S.A.Cotton, Scandium, Yttrium and the Lanthanides:Inorganic and Coordination Chemistry, Encyclopedia of Inorganic Chemistry, 1994, John Wiley & Sons, ISBN 0471936200
3. ^ McCleverty, J.A. and Meyer, T.J., Comprehensive Coordination Chemistry II, 2003, Elsevier Science, ISBN 0080437486, Vol. 3, p. 99 ["Refluxing scandium oxide with triflic acid leads to the isolation of hydrated scandium triflate"]

External links

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